Heatwaves and cardiovascular emergencies in our city, in Italy: pre-Covid-19, Covid-19 and post-Covid-19 characteristics and associated risk during heat days

Abstract Background Recent research reports both direct and indirect impact of the coronavirus disease 2019 (COVID-19) on cardiovascular (CV) health. Existing case-studies mostly focus on the immediate effects, leaving the long-term consequences of the pandemic in this field as yet unrecognised. Purpose The aim of this study was to analyse the changes in CV emergencies’ characteristics during COVID-19 (C, 2020-21) and post-COVID-19 (post-C, 2022) periods in reference to pre-COVID-19 (pre-C, 2017-19) and to provide the associated relative risk (RR) during heat days (i.e., with apparent temperature > 95th percentile of the annual distribution) compared to non-heat days. Methods Ambulance dispatches for CV problems in our city, Italy during May-September in pre-C, C, and post-C were considered. Their characteristics, i.e., mean daily quantity, patients’ age and gender distribution and emergency severity (i.e., fatal, requiring transportation to a hospital, non severe) distribution were compared using Student’s t-test and Fisher’s exact test. For each period, the RR of CV emergencies during heat days in reference to non-heat days was calculated, dividing the number of emergencies in heat days by their number in randomly selected subset of non-heat days, accounting for vacation period. Results In total, 64,881 CV emergencies were reported. In both C and post-C, compared to pre-C, a significant reduction of around 3% in events in women, and of almost 5% in events that required transportation to a hospital, was observed (Table 1). In pre-C, the average daily number of emergencies was 72.8, reduced to 66.5 in C, and back to the pre-pandemic level (72.7) in post-C. Also, the age of patients in post-C was reduced. Interestingly, stratifying by the severity of the emergencies, significant increase in the age for fatal emergencies in both C and post-C was found, together with an age decrease for events resulting in hospital admission. The RR of having a CV emergency in heat days was similar in pre-C, C, and post-C periods (1.11 (95% CI: [1.06; 1.15]), 0.98 ([0.94; 1.03]), and 1.07 ([1.01; 1.14], respectively), with the RR being the highest for fatal emergencies, lower for non severe ones and the lowest for those requiring transportation to a hospital (Figure 1). Conclusions The risk of having a CV emergency is higher in heat days than in non-heat days, in particular for fatal emergencies. The COVID-19 pandemic had a significant impact on CV emergencies, including a temporary decrease in demand for the emergency medical service, also in extreme weather, and a long-term decrease in the mean age of the patients and in the fraction of emergencies requiring transportation to a hospital. Monitoring the trends in upcoming years will be crucial to fully comprehend the impact of the pandemic on CV emergency service demand, as well as of heatwaves.Table 1Figure 1